Leucobacter margaritiformis sp. nov., Isolated from Bamboo Extract

Leucobacter tenebrionis sp. nov., isolated from the gut of Tenebrio molitor

A novel Gram-stain-positive bacterium, designated NB10T, was isolated from the gut of Tenebrio molitor. The isolate was rod-shaped, aerobic, non-motile and non-spore-forming. Colonies of strain NB10T were light yellow, circular and smooth. Phylogenetic analysis based on 16S rRNA gene sequence comparisons indicated that the isolate was related to the genus Leucobacter. Its closest relatives were Leucobacter holotrichiae T14T (97.8 % 16S rRNA gene sequence similarity), Leucobacter zeae CC-MF41T (97.0%) and Leucobacter salsicius M1-8T (96.4%). The DNA G+C content of strain NB10T was 68.8 mol%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization values among strain NB10T and the selected Leucobacter species were ≤83.8 % (ANI-blast), 87.6 % (ANI-MUMmer) and 29.6%, which were below the recommended cutoff values for species delineation. The predominant cellular fatty acids were anteiso-C15 : 0 (39.0%), anteiso-C17 : 0 (35.5%) and iso-C16 : 0 (17.0%). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and glycolipids. The predominant respiratory quinones were MK-11 and MK-10. The cell wall amino acids were Gly, Glu, Tr, Ala, and DAB. Based on these phylogenetic and phenotypic results, strain NB10T can be clearly distinguished from all of the recognized species of the genus Leucobacter and is considered to represent a novel species of that genus. The name Leucobacter tenebrionis sp. nov. is proposed, with the type strain NB10T (=MCCC 1K07072T=KCTC 49728T).

Leucobacter chinensis sp. nov., with plant growth-promoting potential isolated from field soil after seven-years continuous maize cropping

A novel Gram-stain-positive, aerobic, non-motile and rod-shaped bacterium, designated strain NC76-1^T, was isolated from soil from a field that had undergone seven years continuous maize cropping from Liuba town located in Zhangye city, Gansu province, PR China. Colonies of strain NC76-1^T were white, opaque and circular with a convex shape. The isolate was found to be able to grow at 10-40 °C (optimum 30 °C), pH 6.0 to 12.0 (optimum 7.0-8.0) and with 0-5.0 % (w/v) NaCl (optimum 0%). On the basis of the results of 16S rRNA gene sequence analysis, the strain fell within the clade of the genus Leucobacter, showing the highest sequence similarities with Leucobacter iarius 40^T (97.4%), Leucobacter aridicollis CIP 108388^T (97.0%), Leucobacter chromiireducens subsp. solipictus TAN 31504^T (96.7%) and Leucobacter denitrificans M1T8B10^T (96.7%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between NC76-1^T and its closest relatives, L. iarius 40^T, L. aridicollis CIP 108388^T, L. chromiireducens subsp. solipictus TAN 31504^T and L. denitrificans M1T8B10^T were ≤73.5 % and 20.3%, respectively. The genomic DNA G+C content of NC76-1^T was 61.5 mol%. It presented MK-11 as the predominant menaquinone. The major cellular fatty acids were anteiso-C_15 : 0 (49.2 %) and iso-C_16 : 0 (35.7%). The major polar lipids were found to be diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, aminoglycolipid, five glycolipid and one unidentified lipids. The cell wall amino acids were 2,4-diaminobutyric acid, alanine, glutamic acid, glycine and threonine. On the basis of the phylogenetic, phenotypic and chemotaxonomic characteristics, strain NC76-1^T is concluded to represent a novel species within the genus Leucobacter, for which the name Leucobacter chinensis sp. nov. is proposed. The type strain is NC76-1^T (GDMCC 1.2286^T= JCM 34651^T).

Leucobacter soli sp. nov., from soil amended with humic acid

A Gram-positive, non-spore-forming actinobacterium (IMT-300^T) was isolated from soil amended with humic acid in Malvern, AL, USA. This soil has been used for 50+years for the cultivation of earthworms for use as fish bait. Based on 16S rRNA gene sequence similarity studies, strain IMT-300^T was shown to belong to the genus Leucobacter and was closely related to the type strain of 'Leucobacter margaritiformis' L1^T (97.8%). Similarity to all other type strains of Leucobacter species was lower than 97.2 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the IMT-300^T genome assembly and those of the closest relative Leucobacter type strain were 81.4 and 23.3 % (Leucobacter chironomi), respectively. The peptidoglycan of strain IMT-300^T contained l-2,4-diaminobutyric acid as the diagnostic diamino acid. In addition, glycine, d- and l-alanine and d-glutamic acid were found. The peptidoglycan type represents a variant of B2δ (B11). The major quinones were menaquinones MK-10 and MK-11. The polar lipid profile consisted of the major lipids diphosphatidylglycerol, phosphatidylglycerol and moderate to minor amounts of two unidentified phospholipids, two unidentified glycolipids and an unidentified aminophospholipid. The polyamine pattern contained major amounts of spermidine and spermine. Strain IMT-300^T contained the major fatty acids C_15 : 0 anteiso, C_16 : 0 iso and C_17 : 0 anteiso, like other members of the genus Leucobacter. The results of ANI and dDDH analyses and physiological and biochemical tests allowed a genotypic and phenotypic differentiation of strain IMT-300^T from the most closely related Leucobacter species. Strain IMT-300^T represents a novel Leucobacter species, for which we propose the name Leucobacter soli sp. nov., with the type strain IMT-300^T (CIP 111803^T=DSM 110505^T=CCM 9020^T=LMG 31600^T).

Leucobacter muris sp. nov., isolated from the nose of a laboratory mouse

A Gram-stain-positive, rod-shaped, aerobic, non-motile, white, opaque bacterial isolate, designated 924/12^T, was isolated from the nose of a laboratory mouse in Düsseldorf, Germany. The 16S rRNA gene sequence analyses indicated the phylogenetic position of the strain within the genus Leucobacter. Similarity levels over 97 % were recorded between the 16S rRNA gene sequence of strain 924/12^T and the type strains of the species Leucobacter chironomi DSM 19883^T (99.5 %), followed by Leucobacter celersubsp. astrifaciens CBX151^T (97.6 %), Leucobacter celersubsp. celer NAL101^T (97.5 %), 'Leucobacter kyeonggiensis' F3-P9 (97.5 %), Leucobacter zeae CC-MF41^T (97.3 %), Leucobacter chromiiresistens JG31^T (97.1 %), Leucobacter triazinivorans JW-1^T (97.1 %), Leucobacter corticis 2 C-7^T (97.0 %) and Leucobacter aridicolis CIP108388^T (97.0 %). DNA-DNA hybridization and whole genomic comparison, mandatory to taxonomically separate strain 924/12^T from the type strain of L. chironomi, revealed similarity values of 40.4 and 30.8 %, respectively, thus below the threshold of 70 % recommended differentiating between species. The cell-wall amino acids of the novel isolate were diaminobutyric acid, alanine, glycine, threonine and glutamic acid. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, glycolipid and one unknown lipid, whereas the predominant menaquinones were MK-11 and MK-10. The genomic DNA G+C content of strain 924/12^T was 70.6 mol%. Phylogenetic analyses based on the 16S rRNA gene sequences and the phenotypical differences between strain 924/12^T and the other closely related type strains of the genus Leucobacter indicated that strain 924/12^T represents a novel species within the genus Leucobacter, family Microbacteriaceae, for which the name Leucobacter muris sp. nov. is proposed. The type strain is 924/12^T (=DSM 101948^T=CCM 8761^T).

Leucobacter weissii sp. nov., an isolate from activated sludge once described as first representative of the peptidoglycan variation B2δ, and emended description of the genus Leucobacter

Strain S27^T is a Gram-stain-positive, regular rod-shaped, non-motile, non-spore-forming, yellow pigmented actinobacterium which was isolated from an aerated laboratory scale fermenter fed with wastes of a yeast factory. The strain was classified as Microbacterium sp. after the analysis of its peptidoglycan revealed a novel B-type structure established as variation B2δ by Hensel in 1984. As the combination of the peptidoglycan amino acids 2,4-diaminobutyric acid (Dab), threonine (Thr), glycine (Gly), alanine (Ala) and glutamic acid (Glu) is in disagreement with the current genus definition of Microbacterium but is typical of several Leucobacter species, the taxonomic status of strain S27^T was re-examined by a polyphasic study. Comparative analyses of 16S rRNA gene sequences and the occurrence of l-Dab, d-Ala, l-Ala, Gly, l-Thr, d-Glu and lower amounts of l-Glu in the peptidoglycan in combination with the predominating menaquinones MK-11, MK-10 and MK-9, phosphatidylglycerol, and one unknown glycolipid as the major polar lipids (and trace amounts of diphosphatidylglycerol and an unknown phospholipid), a profile with anteiso-C15 : 0, iso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and iso-C17 : 0 as major fatty acids and the G+C value of 70.1 mol% confirmed the affiliation to the genus Leucobacter and revealed that S27^T (=DSM 20621^T =CCM 8762^T) is the type strain of a new species for which the name Leucobacter weissii sp. nov. is proposed. The availability of new data allows for an emended description of the genus Leucobacter.

Nesterenkonia pannonica sp. nov., a novel alkaliphilic and moderately halophilic actinobacterium

An alkaliphilic and moderately halophilic bacterial strain characterized by optimal growth at pH 9.0-10.0 and with 5-7 % (w/v) NaCl, designated BV-35^T, was isolated from water of a soda pan located in Kiskunság National Park, Hungary. Cells of the orange-pigmented colony were Gram-stain-positive, non-motile and non-endospore-forming coccoid rods. The isolate was strictly aerobic, catalase-positive and oxidase-negative. Strain BV-35^T displayed a peptidoglycan similar to type A4α, l-Lys-l-Glu (A11.54 according to www.peptidoglycan-types.info) but containing additionally 4-aminobutyric acid. Menaquinone-7 (MK-7) was the predominant isoprenoid quinone, and anteiso-C15 : 0 and anteiso-C17 : 0 were its major cellular fatty acids. The DNA G+C content of strain BV-35^T was 65.4 mol%. Based on 16S rRNA gene sequence similarities, the novel isolate showed the closest relationship to Nesterenkonia populi GP 10-3^T (97.9 %). The DNA-DNA relatedness between BV-35^T and N. populi was 46.7 %. The distinguishing phenotypic and genetic results of this polyphasic study revealed that strain BV-35^T represents a novel member of the genus Nesterenkonia, for which the name Nesterenkonia pannonica sp. nov. is proposed. The type strain is BV-35^T (=DSM 29786^T=NCAIM B 02606^T).

Description of Leucobacter holotrichiae sp. nov., isolated from the gut of Holotrichia oblita larvae

A Gram-stain-positive bacterium, designated T14T, was isolated from the gut of Holotrichia oblita larvae and was subjected to a taxonomic study. The isolate was rod-shaped, aerobic, non-motile, non-spore-forming and yellow-pigmented. Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that the isolate is related to the genus Leucobacter. Its closest neighbours were the type strains 'Leucobacter kyeonggiensis' F3-P9 (96.8% 16S rRNA gene sequence similarity), Leucobacter celer NAL101T (96.2%) and Leucobacter chironomi DSM 19883T (95.5%). The DNA G+C content of strain T14T was 69.3 mol%, and DNA-DNA hybridization values with closely related strains were <32%. The predominant cellular fatty acids were anteiso-C15:0 (49.3%), iso-C16:0 (16.4%) and anteiso-C17:0 (16.8%). The major polar lipids were aminolipid, diphosphatidylglycerol, phosphatidylglycerol, phospholipid, phosphoglycolipid and unidentified glycolipids. The predominant respiratory quinone was MK-11. Based on these phylogenetic and phenotypic results, strain T14T can be clearly distinguished from all of the recognized species of the genus Leucobacter and is considered to represent a novel species of the genus Leucobacter. The name Leucobacter holotrichiae sp. nov. is proposed, with the type strain T14T (=DSM 28968T=JCM 30245T).

Leucobacter zeae sp. nov., isolated from the rhizosphere of maize (Zea mays L.)

A novel yellow-pigmented, aerobic, rod-shaped, non-motile bacterium, designated strain CC-MF41T, was isolated from rhizosphere soil of maize (Zea mays) collected in Wufeng District, Taichung, Taiwan. Strain CC-MF41T exhibited 16S rRNA gene sequence similarity of 97.5, 97.3, 97.2 and 97.1 % to Leucobacter chironomi MM2LBT (and ‘Leucobacter kyeonggiensis’ F3-P9 and ‘L. humi’ Re-6, the names of which have not been validly published), Leucobacter tardus K70/01T, L. komagatae IFO 15245T and ‘Leucobacter margaritiformis’ A23. However, CC-MF41T and ‘L. margaritiformis’ A23 formed a loosely bound phylogenetic lineage (with a low bootstrap value) associated with species of the genus Leucobacter. In DNA–DNA reassociation experiments, the relatedness of strain CC-MF41T to L. chironomi DSM 19883T was 57.1 % (reciprocal value 29.1 %). The DNA G+C content of strain CC-MF41T was 72.1 mol% and the cell-wall peptidoglycan contained 2,4-diaminobutyric acid, alanine, glycine, glutamic acid and threonine. The major menaquinone was MK-11 and the predominant fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The polar lipid profile of strain CC-MF41T contained major amounts of diphosphatidylglycerol followed by an unidentified glycolipid, phosphatidylglycerol and an unknown phospholipid. Based on its phylogenetic, phenotypic and chemotaxonomic distinctiveness, strain CC-MF41T represents a novel species of Leucobacter, for which the name Leucobacter zeae sp. nov. is proposed. The type strain is CC-MF41T ( = BCRC 80515T = LMG 27265T).